Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with transitional graphical user interface, showing the first image in a sequence, showing our new design;

FIG. 2 is a front view showing the second image thereof;

FIG. 3 is a front view showing the third image thereof;

FIG. 4 is a front view showing the fourth image thereof;

FIG. 5 is a front view showing the fifth image thereof;

FIG. 6 is a front view showing the sixth image thereof;

FIG. 7 is a front view showing the seventh image thereof; and,

FIG. 8 is a front view showing the eighth image thereof.

The outermost broken lines illustrating portions of a display screen or portion thereof form no part of the claimed design. The remainder of the broken lines illustrating portions of the graphical user interface forms no part of the claimed design.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-8. The process or period in which one image transitions to another image forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 